1. Field of the Invention
The present invention relates to a color image processing device for use in conjunction with a color copier, a color printer or the like. More particularly, the invention relates to a color image processing device for producing a corrected color image signal to be applied to a color printer upon processing an original color image signal relayed from an image scanner, thereby reproducing a color image with excellent fidelity.
2. Description of the Prior Art
Heretofore, there has been known a digital color printer which prints a color image in accordance with color data relayed from an optical image scanner which optically scans and reads a color image of an original color document. In such a color printer, a color print with excellent fidelity cannot be obtained insofar as the color data produced from the optical scanner are directly supplied to the color printer. This is due to the fact that the printer has an inherent characteristic in reproducing colors.
To improve the color fidelity of the output color print, it has been proposed to carry out a masking process of the color data prior to supplying it to the color printer. In the typical masking process, a 3-by-3 matrix is used. Representing the color data picked up by the image scanner as R, G and B, and modified color image to be supplied to the color printer as R', G' and B', the following matrix is used. ##EQU1## where A is a 3-by-3 matrix.
However, the color fidelity of the output color print is not yet satisfactory even if the masking process with the 3-by-3 matrix is performed. One possible solution to further improve the color fidelity is to introduce the terms of the increased order color components in the matrix. For example, for the matrix including the terms of the second order color components, the following masking process is to be executed: ##EQU2## where A is a 3-by-10 matrix.
With such a masking process, the color fidelity is further improved. However, no further improvement of the color fidelity cannot be achieved even if the order of the color components were further increased.